Panels for absorbing and utilizing solar energy are well-known and in wide-spread use. Such panels employ the heat energy from the sun to warm liquids or gases for various heating and cooling purposes. Other panels employ photovoltaic cells to convert solar energy directly into electrical energy. The use of photovoltaic cells has been limited because of the high cost of said cells and the fact that only about twelve percent, more or less, of the solar radiation can be converted into electricity. Prior art devices have used reflectors for the purpose of concentrating the solar energy upon photovoltaic cells in an effort to improve their output. However, the increased temperature caused by the uneven distribution of the concentrated solar rays upon the cells together with inadequate cooling often leads to their rapid deterioration.
The curvature of the reflectors used throughout the art covers all the conic sections, but none of the dimensions associated with the sections produce a uniform distribution of energy over the surface of the cells, or a constant selected angle of incidence of the rays after a single reflection from the mirror surfaces.
Since only twelve percent of the radiation impinging on the solar cell is converted into electrical energy, the remaining approximately eighty-eight percent which must be removed from the cell to prevent their overheating is available for domestic purposes such as heating. Thus the calculations based upon the percentage of electrical energy plus the thermal energy utilized for domestic purposes, will bring the cost per watt of utilized solar energy within the cost per watt of energy derived from other sources.
To provide maximum concentration of solar radiation per unit area of concentrated rays, it is necessary to employ reflectors that fit together with a high degree of close packing while satisfying the conditions of uniform distribution of the reflected solar radiation over the photovoltaic cells, and a uniform angle of incidence of the solar rays after a single reflection from the reflectors. These conditions require cone-shaped reflector units of hexagonal shape.
It is, therefore, an object of the present invention to provide an array of closely packed reflecors having a plurality of inclined reflecting surfaces which provide a uniform distribution of energy over the surface of the photovoltaic cells to achieve high energy conversion.
It is another ojbect of the invention to capture and use the energy in the fluid which cools the solar cells.
Still another object of the invention is to apply a pressure on the inner surface of a solar panel window which will equalize the pressure developed by the wind on the outer surface.